Lecture 6 Flashcards
What is the patterning of the head, body and limb movements relative to the patterning of the environmental objects and events?
Coordination
* your movement patterns are releated to your setting
What is the number of independent components of the system and the number of ways each component can vary?
Degrees of freedom
* this is refering to all the degrees of freedom - head to toe
think about the wrist having two degrees of freedom
also depends on the task - simple tasks (writing on a peice of paper) require less degrees of freedom
* walking
Body needs to know how many degrees of freedom are needed so that it can coordinate muscles and joints to create movement
differeinate an open loop vs closed loop control system
In the open loop system you do the task and its done (no feedback = open loop = didnt connect back to brain)
In the closed loop system you do the task then get the feedback
Would a very discrete movement that only needs to happen once be open loop or closed control system?
Open loop
* does not require feedback for the system to improve
* think tapping pen - you don’t need feedback from your body to know if it was effective or not
Walking w/ a new pair of shoes. Would this be an open loop or closed loop control system?
Closed loop
You need that feedback to see if they fit right (might get a blister if you don’t get that feedback)
* You’re getting nociceptive sensory feedback
Is most feedback we get from a closed loop system sensory
Yes (shoe example)
In open or closed control system in which one do you think contorlling the degrees of freedom (leading to more coordinated body movement) is more important?
Closed loop
because the more feedback we get the more efficent we are at coordinating the limbs and controlling those degrees of freedom approperatly
activities that require a great deal of corodination - or have lots of movement components to them are open or closed loop
closed loop - we need that feedback to make us more effeicent at what were doing
KNOW: the two motor contol theries try to tell us how we learn how to move efficently
A memory based construct that controls coordinated movement
* something has to be in the memory in order of the individual to be able to utilize it to perform the coordinated movement
*
Motor program (Motor program based theroy)
The memory representation of a class of actions that share common invariant characteristics; basis for controlling a specific action with the class of actions
Generalized motor program (Motor program based theroy)
* essentially takes those motor programs and modifies them slightly to make new action happen
Unique set and charcateristics that do not vary from one performance of the action to another
Invariant features (motor program based therory)
Sitting in chair to standing up
* all compoents of that movement dont change each time you do it (the parts that dont change are your invariant features)
Features that can be varied from one performance of the action to another; must be added to the invarient feastures for the person to meet the skill demands of varying situations
Parameters
Essentially new parts of the task that you’ve never done before but piggy back on the invarient features
* think having an active fire alarm instead of a drill
* the invarient features are the things that are the same between the drill and real thing
* The paramateres are the features that would be varried from the invarient features (think speed / urgency changing would be parameters)
EX: Walking down the hallway what are the invarient features?
Now what changes if they now need to speed up
Invarient feautes: Hip flexion / extension / dorsiflexion / plantar flexion (etc…)
* these are essentailly things that don’t change from trial to trial
Parameters if they need to speed up: longer stride length / cadance / perpulsion
* essentailly adding things onto invarient features to adapt to the new environment
Lifting a gallon of water from the car:
* what are the invarient features
What would be the parameters w/ lefting two gallons
invarient features: Trunk flexion / extension / elbow flexion / finger flexion - etc…
Parameters: wider BOS
* basically anything that would impact the invarient features of that motion
A set of rules that serves to provide the basis for a decision
Schema
KNOW: The more you are exposed to different parameters the more likely you are to develop a set of rules for how you’re going to respond in that situation
* if you are frequently picking up water from the back of your car - your body will develop a schemia within that new parameter (which muscles to activate)
* essentially developing another motor program for it
* Called motor response schema
The more we do that new skill or action w/ thsoe new parameters the better at this new skill we get
Motor Program based theroy
KNOW:
Cognitive phase = developing those motor programs (motor program based theroy)
Associative phase = adding in new parameters
Autonomous stage
* getting good at adapating to those new parameters
* they have added motor schemia to these new parameters (rules for these differing parameters)
Obtain coordination of movement primarily from information coming in from the environment as well as the degrees of freedom of the body is what theroy
* Not so much the brain deciding how were going to create this motor program - but were going to take in information from the environment and relate it to the limbs and muscles and joints and how all of that works together
* and from that we create a motor program
Dynamical systems theroy
From a motor prespective we dont don’t contorl in a nice linear way is known as
Nonlinear dynamics
we learn a ton at the start and then it slows down
(dynamical systems theroy)
what theroy belives that there is a distinct coordination of patterns that can develop spontaneously form environmental exposure
Dyanmical systems theroy
Remember - this isnt really the brain as much as the environment teaching us
The environment affected his movement pattern to make him take bigger steps is what theroy
Dynamical system theroy
the requirements of the environment or situation creating a non-linear change in the motor program so the person can be sucessful w/ the activity
The behavioral steady state of a system
Stability (DST)
* when a system is slightly perturbed it will return to a stable state
Preferred behavioral state
Attractors (DST)
* most energy-efficent states
Often the same as stability
KNOW: Body will always return to its most efficent performance (DST)
Functionally specific variables that define the overall behavior of a system; then enable a coordinated pattern of movement to be reproduced and distinguished from other patterns
* Essentially features of the movement that need to occur over and over again
* Kind of like invarient features
Order parameters (DST)
The variable that when its increased or decreased will influence the stability and character of the order parameter
* similar to parameters of GMP
Control parameter
The coordinated pattern of movement self-organizes within the framwork of the characteristics of environmental conditions, the task demands, and limb dynamics
Self-organization
this is the big difference between the two theroies
* The environment has a significant influence on how the motor program develops in in the DST
* How is that information from the environment coming in and the individual is self organizing that (so its not one specific generalized motor plan - but is fluid in the environment the person is in)
Walking down the hall way
* attactors?
* control parameters if were walking in a hurry
* self organization
Attractors: size / strenght / prevous experiences would effect this (puts them in most energy efficent state)
control parameters: will leave that attractor because were speeding up
* more activiation of some muscles - use greater joint ROM etc… (essentially the same as parameters form before)
Self-organization: how the information from the environment is taken in and managed so you can get down that hallway in a hurry
Lifting a gallon of water
* attractors
Attractors: affected by flexibility / size / strength / height
Control parameters for lifting heavier gallon of water:
* changing BOS / increased elbow flexion / bicep control
Self organization: taking in whatever those influences are in the environment and relating it to the task
Dynamical systems theroy: Instead of creating a gneralized motor program and creating different schema that are going to modify that as needed we have instead coordianted structures - which are muscle senergies
* instead of activiating different muscles to perform a coordinated pattern - once you’ve done a pattern enough times you create a muscle senergy pattern so theres litteraly one activation point that reaches all of that instead of several
Walking vs Running
Generalized motor program says: you have one motor program associated w/ walking and a different motor program associated w/ running
Dyanmicial systems theroy says: your body reaches a point where it has a specific attractor state that it likes for walking and another one that it likes for running and in that change when you become unstable - chaing the order parameter (speed in this case) we will self organize to get back to whatever that stable attractor sate is
* so essentially were at a steady state when walking then we change the speed to running and will get back to a steady state when running (adapating to the new environment)
* So essentailly the body self organizes to return to its new attractor state at the faster speed
DST: Walking and running are two attractor states; as the order parameter becomes unstable (speed), the gait pattern self-organizes to become stable at the faster speed
Amount of tension in the muscle is sensed by the
golgi tendon organs
Amount of stretch in the muscles is sensed by
muscle spindles
Where are joint receptors
In the capsule
* sense force and rotation applied to the joint, and joint movement angle
KNOW: people who have good proprioception are able to generate the commands for movement much more quickly
* musch more effective at starting and stopping a movement - or starting and adjusting a movement as needed
Also have better coordination control / postural control (balance) if we have good proprioception
S-atial-temporal coupling between limb segemetns is helped by proprioception
Chopping left cranial nerve = monocular vision
* dont estimate distance / size of objects as well
* also have more head movement to compensate for that (moving head more = have to change the motor program)
Binocular vision
* judge distane and speed better
Where is central vision located?
middle 2-5 degrees
How many degrees of visual field in each eye?
200 horizontally
160 vertically
peripheral visual field is all but that middle 2-5 degrees
what has. the greater impact on motor contorl. losing central vision vs peripheral
peripheral (much bigger degrees)
* going to have to make adaptations in head movement
What are our 2 kinds of optic flow?
Vision we get from perception of movement and vision we get from action of movement
As the person is moving through space vs how they’re preseving the space around them
vision of perception
vision of action
what is macular degeneration?
Losing that central vision first then it expands out
